SU953002A1 - Composition for liquid boronizing of products from ferrous metals and alloys - Google Patents

Description

The invention relates to the field of chemical-heat treatment of metals and alloys and can be used in the machine-building, metallurgical, chemical and other industries of the industry.

A known composition for liquid boronation of metals, containing borax and boron carbide. The optimum is the composition, wt.%: Borax 70-60, boron carbide 30-40. Booting temperature of EBV-IOO C, load time 4-6 h. L.

The disadvantages of this melt are its large ablation with processing parts due to the high viscosity, the difficulty of washing the melt from the products, which makes it difficult to use technology on an industrial scale. The cost of the melt containing 40% boron carbide and 60% borax is em 3.84 rub. for 1 kg. The boride layer consists of two phases: FejB and FeB. The amount of high-boride FeB phase in the boride coating when reaches 32%.

The closest to the proposed technical essence is the composition for boronation, containing, wt.%: Boron carbide 30-40, chlorine sodium 10-15, borax - the rest. Boronization temperature, holding time 5-6 h 2.

The disadvantages of this composition are: the large cost (1 kg of melt containing 30% boron carbide, 10% sodium chloride, 60% borax, costs 2.57 rubles), a relatively high content of high-porous

10 of the FeB phase in the diffusion boride coating (on the Arc-iron at 5 h, the FeB content is 30-35%), which leads to great brittleness of the boride layer, and the danger and difficulty of working with borax, which includes 10 water molecules (-lOHjO) .. Requires additional borax drying. In the case when in a storm

20 moisture remained, melt foaming is possible and its emission.

The purpose of the invention is to reduce the brittleness of the coating by reducing the content of the FeB phase, reducing the cost of the melt, improving working conditions and safety.

The goal is achieved by that; that the composition .. containing carbide

Claims (4)

30 boron and sodium halides additionally contain sodium oktoborate in the following ratio, wt.%: Boron carbide 2-10 sodium oktoborate 60-85 sodium halides .5-38 In addition, sodium fluoride, sodium chloride and a mixture of fluorine are used as sodium halides yes and sodium chloride in the ratio of 1: 3-6. The boring is carried out in the melt of the following composition, wt.%: Sodium oktoborate (Na BgOj) 60-85, boron carbide powder 2-10, sodium chloride or fluoride or a mixture of them — the rest Boronization temperature 850 950 s, processing time 1-5 h The boronization is carried out in a metal cup in the open air. Example. A metal crucible was loaded, wt.%: Sodium oktoborate 75, sodium chloride 15, sodium fluoride 5, boron carbide 5. At exposure, samples from CX.X12M at 950 ° give a boride layer for 1 hour with a thickness of 30 µm for 5 hours - 80 mkm The FeB phase in the boride layer is 20 µm. On Archcom-iron in a hot melt for 5 hours at 850 ° С, layers with a thickness of 100 μm and 160 μm were obtained. Example2. In the melt containing, wt.% G, sodium oktoborate 78, sodium chloride 15, sodium fluoride 5, boron carbide 2, at 900 ° C, a boride layer with a thickness of 150 µm was obtained on ArcMon for 5 hours. Example 3. In a melt containing, in wt.%: Sodium oktoborate 85, sodium fluoride 5, boron carbide 1 in 5 hours, a boride layer 160 μm thick was obtained on Arc-iron. PRI me R 4. In the melt containing, wt.%: Sodium oktoborate 80, sodium chloride 15, boron carbide at 5 h on Art. 5XNM. Boride layer 30 μm thick was obtained, on Art. Y8-60 microns. Example5. In the melt containing, wt.%: Sodium oktoborate 60, sodium chloride 30, sodium fluoride 5, boron carbide 5, a boride layer 100 μm thick was obtained on ArcMon in 5 hours. Example In the melt containing, wt.%: Sodium oktoborate. 6 sodium chloride 38, boron carbide 10, at 500 ° С for 3 hours at st. Y8 is obtained boride layer with a thickness of 30 microns. Example. In the melt containing, wt.%: Sodium oktoborate 85, sodium chloride 5, boron carbide 10, for 3 hours at Art. Y8 of the recipients is a boride layer with a thickness of 55 µ. 3, a boride layer 60 μm thick was obtained. In this way, the use of the predicted melt reduces the cost of the boring process, reduces the brittleness of the coating, and improves the working conditions and safety measures. The proposed melt is cheaper than the known E 1.5-2.4 times. The proposed melt improves the quality of the coating. The content in the boride coating of the high-borne FeB phase is 20-24%, i.e. 10% less than what is known, and as a result, the fragility of the diffusion layer is reduced by 10%. In addition, the melt provides improved working conditions; The sodium oktoborat, in contrast to borax, does not contain moisture, so there is no danger of foaming and melt ejection when loading and working with it, which leads to an improvement in safety. Additional salt drying is also eliminated. Use as sodium halide or sodium fluoride or mixtures thereof accelerates the boronization process and improves the quality of the coating. Claim 1. Composition for liquid boiling of products from ferrous metals and alloys, containing boron carbide and sodium halides, and with the fact that, in order to reduce the brittleness of the coating by reducing the content of the FeB phase, reduce the cost of boring, improve conditions labor and safety, it additionally contains sodium oktoborate in the following ratio of components, wt.%: Boron carbide 2-10 sodium oktoborate 60-85 Sodium halogenides - 5-38 2. The composition according to claim 1, from l, and also with the fact that sodium fluoride is used as sodium halides. 3. The composition according to claim 1, characterized in that sodium chloride is used as sodium halogenide. . 4. The composition according to claim 1, about tl and h ayush and with IeM, that as g59530026 sodium logides use a mixture of 1. Voroshnin L.G. and L. Hovich L.S. fluoride and sodium chloride in the ratio- Boronovy steels M., Metallurnium 1: 3-6.g. 1978, p. 52-56. Sources of information, metal processing, 1969, 5, taken into account in the examination of 5 s. 74-78. .2. Metallurgy and thermal science